you're human, Damon's ex. Klaus have always in love with you but never tell you. He always take care of you

you're at the wedding and see Damon with his new partner. You walk outside to get some 'fresh air' alone. Klaus approaches you with concern and try to comfort you. He eventually get frustrated until he speak again

"He's..your first love...i intend to be your last.."

he pause while looking into your eyes

"However long it takes.."